Section1

Thyroid-Stimulating Hormone

The pituitary gland (located at the base of the brain) controls hormone production in your body. More specifically, it produces thyroid-stimulating hormone, or TSH, which tells the thyroid gland how much T4 (thyroxine) and T3 (triiodothyronine) to make.1

Learn more about the role of the thyroid (1:16)

What does the TSH level in blood mean? TSH levels indicate how much T3 and T4 the thyroid gland is producing. There is an inverse relationship between T4 and TSH. For example, when there is abnormally low T4 and high TSH, this is hypothyroidism. On the other hand, hyperthyroidism occurs when there are abnormally high levels of T4 and low levels of TSH.1

Two common types of thyroid disorders1:

  • Hypothyroidism, or underactive thyroid
  • Hyperthyroidism, or overactive thyroid
Section2

Thyroid Disorders

HYPOTHYROIDISM1

When the thyroid produces low levels of T4 and the TSH level is high, this is called hypothyroidism, or underactive thyroid. When a patient is diagnosed with underactive thyroid, it means that the thyroid gland is not making enough T4 hormone to keep the body working as it should.

HYPERTHYROIDISM1

When the thyroid produces a very high level of T4 and the TSH level is too low, this is called hyperthyroidism, or overactive thyroid. Overactive thyroid means the thyroid makes too much thyroid hormone due to a signaling problem between the patient's brain and thyroid, causing the pituitary gland to stop or slow production of TSH.

Section3

Risk and Prevalence2-4

Hypothyroidism is considered to be one of the most common clinical disorders of the thyroid in the US. An estimated 20 million Americans have some type of thyroid disease. Hypothyroidism is more common in women than in men.

DID YOU KNOW?

  • 1 in 8 women will develop a thyroid disorder in her lifetime3
  • Up to 60% of those with a thyroid disease are actually unaware they have it3
  • Women may be 5x-8x more likely to have thyroid problems than men3
References:
  1. Garber JR. Thyroid Disease: Understanding Hypothyroidism and Hyperthyroidism. 4th ed. Boston, MA: Harvard Health Publications; 2015.
  2. Braverman LE, Cooper DS, eds. Werner and Ingbar's The Thyroid. A Fundamental and Clinical Text. 10th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013.
  3. General Information/Press Room. American Thyroid Association website. http://www.thyroid.org/media-main/about-hypothyroidism/. Accessed March 21, 2016.
  4. American Thyroid Association. Hypothyroidism. A Booklet for Patients and Their Families. http://www.thyroid.org/wp-content/uploads/patients/brochures/Hypothyroidism_web_booklet.pdf. Published 2013. Accessed February 1, 2016.

How many patients do you see with thyroid disorders?

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